Metal roofs can be loud. The half of the house that was rebuilt has a standing seam roof on 8" SIPS on the pine ceiling (no attic). That means 3/4" OSB (I think), 8" of rigid foam, another 3/4" OSB and 1" of pine. I figured that 8" of foam would insulate it not only from heat transfer but also noise. Not so much, when it rains you sure know it upstairs. Probably needs an air layer to deaden the sound.